With the development of a display technology, displays for use in electronic devices have been improved in terms of various factors for improving screen visibility, such as resolution, brightness, a viewing angle, and the like. Not only displays for desktop personal computers (PCs) or note PCs which generally provide at least 10 inch screen but also displays for portable user terminals continue to be improved in terms of a screen size, resolution, brightness, and the like.
As the screen visibility of electronic devices are improved, a user of an electronic device uses a method of dimming a screen of the electronic device or limiting a viewing angle of the screen so as to prevent the screen from being easily recognized by another person. For example, the user attaches a security film to an entire display of the electronic device or limits the viewing angle of the display by hardware.
Hardware-based screen security is applied to an entire display of an electronic device, and may thus restrict flexible use of a screen by a user. Therefore, instead of the hardware-based screen security, software-based screen security is used. According to the software-based screen security, a security image is located at a top layer of an area to which screen security is to be applied so that an effect which is similar to that of a security film or an effect of limiting a viewing angle is brought about.
The hardware-based screen security not only limits the use of a screen as described above, but also requires an additional cost for the hardware and is prone to easy removal of the hardware. In the case of the software-based screen security of the related art, since a security image hides a part of a screen like a security film, content corresponding to an area where the security image is located undergoes security processing en bloc. For example, if a user applies the software-based security of the related art in order to edit an important paper with portable document format (PDF), a security image is generated on an area where a PDF program is displayed so that the area may be dimmed. However, according to this method, even when the user disposes, on the area, a program for which security is not required, such as an Internet browser (e.g., Google maps site) or a Windows explorer, the security image has an effect thereon, so that the user may experience inconvenience in checking information (e.g., map information or the like) of the program for which program is not required.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.